QUANTITATIVE DETERMINATION OF TOTAL HARDNESS IN DRINKING WATER BY COMPLEXOMETRIC EDTA TITRATION
J. JUAN1 and K. MENDOA1 1
NATIONAL INSTITUTE OF MOLECULAR BIOLOGY AND BIOTECHNOLOGY, COLLEGE OF SCIENCE UNIVERSITY OF THE PHILIPPINES, DILIMAN, QUEZON CITY 1101, PHILIPPINES DATE SUBMITTED: 6 APRIL 2015 DATE PERFORMED: 17 MARCH 2015
ABSTRACT
The dri!i" #$%er Hidden Spring, #i%h NH &'NH() *+-%i+ $* .-/er $d EBT Eri+hr+2e B$! T3 $* idi$%+r, i* %i%r$%ed #i%h EDTA e%h4 e%h4ee eedi$ di$2i 2ie%e e%e%r$ %r$$e% $e%i i $id3 $id3 *+-%i *+-%i+ + .4 +25e +25e6+2 6+2e%r e%ri i %i%r$% %i%r$%i+ i+ %+ de%er2i de%er2ie e i%* %+%$ %+%$ h$rde h$rde** ** +r %+%$ %+%$ 2ier$ 2ier$ +%e +%e%7 %7 The EDTA EDTA *+-%i *+-%i+ + i* *%$d$rdi8ed .4 %he 5ri2$r4 *%$d$rd C$CO & #i%h 9979: 5-ri%47 The re*-%i" $;er$"e 2+$r +e%r$%i+ +< EDTA $<%er %hree &3 %ri$* i* 0700=9 M, #hie %he $-$%ed %i%er i* 07=9& 2" C$CO & 5er 2L +< EDTA7 EDTA7 The ed5+i% #he %he #$%er *$25e #$* %i%r$%ed #$* +.*er;ed #he %he ++r h$"ed
red %+ e$r>.-e7 The %he+re%i$ %+%$ h$rde** +< %he dri!i" #$%er i* ?0@7==9 552 C$CO& #hih #$* +.%$ied
INTRODUCTION
Water is a er! i"#$rta%t e&e"e%t i% $'r eer!(a! &ies si%)e it is 'se*'& i% "a%! "a%! as#e as#e)t )ts s + i%(' i%('st str! r!,, -ea& -ea&tt-,, "e(i "e(i)i )i%e %e,, "ate "ateri ria a&s #r$( #r$(') ')ti ti$% $%,, "ar.et, a%( "a%! "$re/ T-e -'"a%
$(! $(! is "a(e "a(e '# &ar &are&! e&! $* ate ater, r, -i) -i)- "ea% "ea%s s it is i"#$ i"#$rt rta% a%tt t$ e )$%s)i$'s a$'t t-e a)t'a& )$"# )$"#$s $sit iti$ i$% % $* t-e t-e ate aterr e are are ta.i% i%/ A (ri%.i% ater )a% eit-er e ta# $r '%#r$)esse(, (isti&&e( + -i)- is *ree
$* i"#'ri i"#'ritie ties, s, $r "i%era "i%era&i3 &i3e( e( + t-e $%e $%e )$%t )$%ta ai%i% i%i% "i%er i%era& a&s s s')s')- as )a&)i'", "a%esi'", ir$% a%( "a%a%ese/ T-e #rese%)e $* "i%era&s i% a (ri%.i% ater, )$""$%&! )a&)i'" a%( "a%esi'", -i)- are $$( *$r t-e $(!, "a.es h$rde** $* ate aterr 4-ar 4-ar( (// T-e T-e %+%$ h$rde** ater e%era&&! "eas'res t-e 'a&it! $* ater $r t-e t-e t$ta& ta& a"$'%t $* "i%era&s #rese%t i% it/
Et-! Et-!&e &e%e %e(i (ia" a"i% i%et etet etra raa) a)et eti) i) a)i( a)i( EDT EDTA;, t-e t-e 'se( 'se( titra itra%t %t i% t-is t-is e#er e#eri"e i"e%t, %t, is a% a"i%$ a"i%$)ar )ar$ $! !&i) &i) a)i( a)i( a%( a%( a )-e& )-e&at ati% i% ae% ae%t, t, -i) -i)"ea%s it -as t$ 2; $r "$re r$'#s )a#a&e $* )$"#&ei% it- a "eta& i$%/ T-e )$"#&ete&! #r$t$%ate( *$r" F!"#$% $% 1&, i s a $* EDTA DTA, H 6 < <2= F!"# -ea#r$ti) ea. a)i(/
I% t-is e#eri"e%t, t-e t$ta& -ar -ar(%es (%ess s $* t-e (ri% (ri%. .i% i% ater Hidde Hidde S5ri" S5ri" as as (eter (eter"i% "i%e( e( ! )$"#&e$"etri) EDTA titrati$%/ +25e6$% 6$%i+ i+ re$%i+ re$%i+ i%$&es A +25e rea ea) )ti$ ti$%s $* t-e '%(is %(iss$ s$)i )iat ate( e( %e'tra& "$&e)'&es a%( t-e )$"#&e i$%s i$%s i% t-e t-e s$&'t &'ti$%8 i$%8 t-e *$r *$r"e( )$"#&e "'st e er! s$&'&e/ I% a +25e6+2e%r +25e6+2e%ri i %i%r$%i+ %i%r$%i+, a s$&'t s$&'ti$% i$% )$%tai%i% *ree "eta& i$%s is titrate( itit- a s$&'t s$&'ti$ i$% % $* a i"$d + a% i$% )a#a&e $* #r$i(i% "$re t-a% $%e #air #air $* e&e) e&e)tr tr$% $%s s t$ a "eta "eta&& i$%/ i$%/ Lia ia%(s are a&s$ )a&&e( he$%i" $"e%* -i) -i)- )a#t )a#t'r 're e "eta "eta&& i$%s i$%s #rese%t i% ater/ W-e% a )-e&ati% ae% ae%tt is i%$ i%$& &e( e(,, t-e t-e )$"# )$"#&e &e is )a&& )a&&e( e( a he$%e/ A titrati$% it- a )-e&ati% ae%t is )a&&e( a he+2e%ri %i%r$%i+ + a s#e)i9) t!#e $* )$"#&e$"etri) titrati$%/
F!"#$% 1/ Str')t're $* EDTA *'&&! #r$t$%ate( *$r";
F!"#$% '/ Str')t're $* EDTA )$"#&ete&! (e#r$t$%ate( *$r";
EDTA i% its )$"#&ete&! (e#r$t$%ate( *$r" F!"#$% '; is a Leis a)i( it*$'r >; %eatie&! )-are( )ar )ar$ $!&a !&ate r$ r$'#s '#s a%( t$ t$ 2; tertiar! a"i%$ r$'#s + si 6; i%( i%(i% i% sites ites i% t$ta t$ta&& + t-at -at )a% ($%ate si 6; #airs $* e&e)tr$%s t$ a "eta& i$%/ T-e "eta& i$% i&& )$"#&eate it- EDTA #arti)'&ar&! i% t-$se t-$se si 6; 6; r$'# r$'#s s t$ satis satis*! *! t-e )$$r )$$r(i% (i%ati ati$% $% %'"er %'"er $* t-e "eta& "eta& i$%/ i$%/ As a res'& es'&t, t, t-e t-e "eta "eta&? &?ED EDT TA )$"#& )$"#&e e is er! er! sta&e sta&e si%)e si%)e EDT EDTA *$r"s *$r"s a )ae?& )ae?&i. i.e e str')t str')t'r 're e ar$'% ar$'%( ( t-e "eta& i$% F!"#$% (;/ Its #r$# #r$#er ert! t! as a &ia &ia%( %( i% t-e t-e "eta "eta&? &? EDTA EDTA )$"#&e )$"#&e is -ea(e% -ea(e%tate tate as it -as t-e ai&it! t$ i%( t$ t-e "eta& i$% i$% si si 6; 6; ti"e ti"es/ s/ T-e T-e %'" %'"er er $* )$$r )$$r(i% (i%ati ati$% $% sites sites (e#e% (e#e%(s (s $% t-e si3e $* t-e "eta& i$%, 't a&& "eta&? EDTA )$"#&ees rea)t i% a rati$ $* 1:1, -i)- "ea%s t-e! #r$(')e $%&! $%e e%(#$i%t/ e%(#$i%t/ M$re$e M$re$er, r, t-e "eta& "eta& i$% i% t-e )$"#&e t-e% a)ts as a Leis Leis a)i( a)i( itit- EDTA EDTA as t-e Leis Leis ase ase// EDT EDTA as a &ia &ia%( %( is a e ea. a. a)i(/
e%(# e%(#$i $i%t %ts s t-at t-at are are -ar -ar( t$ (ete (ete)t )t si%)e t-e starti% a%( e%(i% )$&$rs are a&"$st t-e sa"e/ T-'s, a s$&'t &'ti$% i$% itit- a #H $* 10 is 'se( 'se( e)a'se t-e )$&$r $* t-e "eta&?EBT )$"#&e ('e t$ a""$%ia '@eri% is i%e i%e re( a%( a%( t'r t'r%s )&ea )&earr &'e &'e at e%(#$i e%(#$i%t8 %t8 t-e )$&$r )$&$r )-a%e )-a%e i&& i&& e eas! t$ (isti%'is-/ A&s$, t-e 2ii2-2 *+-%i+ 5H *$r )a&)i'" t$ )$"#&eate it- EDTA is 7/, -i&e it is 10 *$r "a%esi'" + a%( s$ a #H $* 10 is )-$ )-$se% *$r *$r t-e rea)ti a)ti$ $% t$ $))'r/ F!"#$% (/ Str')t're $* EDTA it- a (ia&e%t "eta& i$% "eta&?EDTA )$"#&e;
M$st i%(i)at$rs i%(i)at$rs *$r )$"#&e )$"#&e$"et $"etri) ri) titrati$%s are $ra%i) (!es .%$% as "eta&&$)-r$"i) "eta&&$)-r$"i) i%(i)at$rs/ T-e! *$r" sta&e )$"#&ees it- "eta& i$%s/ I% t-is e#eri"e%t, Eri$)-r$"e B&a). T EB EBT; as 'se 'se( as a% i%(i i%(i) )at$r t$r e)a'se it is a&s$ a )-e&ati% ae%t a%( a%( its its )$"# )$"#&e &e es -ae -ae (i@e (i@erre%t e%t )$&$rs *r$" t-e reae%ts/ It )$%tai%s t-r t-ree ; ; i$%i i$%i3a 3a& &e e #r$t #r$t$% $%s s a%( a%( is re#r e#rese% ese%te te( ( as In i% t-e )-e"i)a )-e"i)a&& e'ati$%s/ A&i.e t$ EDTA, EBT is a&s$ a ea. a)i(, a%( s$ are "$st "eta&&$)-r$"i) i%(i)at$rs/ T-e H?H>= '@e '@err s$&' s$&'ti ti$% $% as as 'se( e)a'se t-e #$er $* t-e a)i( (iss (iss$ $)ia )iati$% i$% )$%s )$%sta ta%t %t # a; $* a""$ a""$%ia %ia is /2 /26, 6, -i) -i)- is er! er! )&$se t$ 10 + t-e (esire( #H *$r t-e e#eri" e#eri"e%t/ e%t/ A asi) '@er '@er s$&'ti$% s$&'ti$% as as a((e( ((e( e)a e)a's 'se e t-e t-e rea ea)t )ti$ i$% % "'st "'st ta.e ta.e #&a)e #&a)e it-i% it-i% a )$%st )$%sta% a%tt #H/ A #H $* 10 is re'ire( t$ a&&$ t-e t-e )$"# )$"#&e &e es Ca Ca?E ?EDT DTA A a%( a%( M? M? EDTA t$ *$r" st$i)-i$"etri)a&&! a%( -ae a s-ar#er e%(#$i%t/ T-e '@er as as )-$s )-$se% e% a&s$ a&s$ e)a e)a's 'se e t-e t-e EBT EBT i%(i)at$r i%(i)at$r -as (i@ere (i@ere%t %t #r$#ert #r$#erties ies i% (i@ere%t #H ra%es/ I* t-e #H a&'e 'se( 'se( as &es &ess t-a% -a% 6/, /, a )$&$ )$&$rr tra%siti$% *r$" i%e re( t$ re( i&& e $sere(/ M$re$er, i* t-e #H a&'e is reater t-a% 11/6, t-e )$&$ )$&$rr tra%si tra%siti$ ti$% % i&& i&& e *r$" *r$" i%e i%e re( re( t$ $ra%e/ B$t)$%(iti$%s -ae
EDTA (i@ers it- ar!i% #H &ee&s F!"#$% $% );/ At #H 10, EDTA is F!"# re#rese%te( as Y )* i% e'ati$%s/ T-is '%#r$ '%#r$t$ t$%at %ate( e( &ia%( &ia%( is res#$ res#$%si %si&e &e *$r t-e *$r"ati$% $* t-e )$"#&ees $* EDTA/ T-e e&e)tr$% #airs $* EDTA are $%&! aai&a&e t$ t-e "eta& i$% -e% t-e a)i( a)i( is (iss$) (iss$)iat iate(/ e(/ Be)a' Be)a'se se $* t-is t-is,, t-e t-e e@e) e@e)ti tie e%e %ess ss $* EDT EDTA is str str$%&! %&! a@e) a@e)te te( ( ! t-e t-e #H/ #H/ T-e i%)reas i%)rease e i% t-e )$%)e%trati$ )$%)e%trati$% % $* H = i$%s ('e t$ a &$ #H "a! i%ter*ere it- t-e )$"#&eati$% $* t-e "eta& i$%s a%( EDTA/ H$eer, "a%! "eta& i$%s )$"#&eates it- -!(r$i(e i$%s a%( s$ t-e e@e)tie%ess $* EDTA i&& a&s$ e re(')e( at a -i- #H &ee&/
F!"#$% )/ F$r"s $* EDTA i% (i@ere%t #H &ee&s
T-e (eree $* i$%i3ati$%, , is t-e reas$% -! t-e )$%(iti$%a& stai&it! )$%sta%t $* EDTA aries it- #H/ At a #H $* 10, t-e $* EDTA is /5 10 ?1 $r 0/5, -i)- "ea%s t-e )-a%)e is -i-er t-at EDTA i&& e (iss$)iate( a%( (is#& is#&a a)e i$%s i$%s i% a rea ea) )ti$ ti$% Ta+,% 1;/ B't i* t-e #H is i%)rease(, t-e e%(#$i%t i&& e t$$ s-ar#/
#$is$%i% + it i%(s t$ t-e &ea( a%( t-e )$"#&e is se)rete( t-r$'- t-e #ati #atie% e%t ts s 'ri% 'ri%e/ e/ e%e e%era ra&& &&!, !, EDT EDTA re(')es t-e rea)tiit! $* t-e "eta&/ I% t-is e#eri"e%t, EDTA is 'se( t$ (eter"i%e t-e t$ta& a"$'%t $* )a&)i'" a%( "a%esi'" i$%s #rese%t i% t-e (ri%.i% ater Hidde S5ri"/ It is e#resse( as ##" CaCO /
METHODOLOGY Ta+,% 1/ Ga&'es $* > *$r EDTA at (i@ere%t #H
-H
)
-H
2/0 2/5 /0 >/0 5/0 6/0
/7 10 ?1> 1/> 10 ?12 2/5 10 ?11 /6 10? /5 10?7 2/2 10?5
7/0 /0 /0 10/0 11/0 12/0
) >/ 5/> 5/2 /5 /5 /
10?> 10? 10?2 10 ?1 10 ?1 10 ?1
EDTA -as "a%! i%('stria& 'ses + it )a% )a% e 'se( 'se( t$ #re #ree% e%tt '%a '%a%t %te( e( "eta&s $r i"#'rities *r$" rea)ti% $r -ai% %eatie e@e)ts $% #r$(')ts/ I% #ers$%a& s.i% )are #r$(')ts, EDTA #'ri #'ri9e 9es s t-e" t-e" ! i%( i%(i% i% t$ *ree *ree "eta& i$%s8 it seres as a #reser #reserati atie/ e/ EDTA EDTA re"$ re"$es es "eta& "eta& i$%s *r$" e%3!"es t-at )a' )a'se s#$i& #$i&a ae i% *$$(/ It re(')e (')es s t-e -ar -ar(%es (%ess s i% t-e t-e #r$) #r$)es essi si% % $* ta# ta# ater t$ e)$"e a s-a"#$$ $r s$a# *$r *$r e%-a% e%-a%)i% )i% t-e e@e)t e@e)ti ie%e e%ess ss $* )&ea )&ea%s %si% i% $* t-e t-e #r$( #r$(') ')tt e)a e)a's 'se e )a&)i'" a%( "a%esi'" i$%s -i%(er t-eir t-eir )&ea%i )&ea%i% % a)ti$ a)ti$%/ %/ I% tet teti&es i&es,, it #re #ree% e%ts ts t-e t-e (is) (is)$& $&$r $ri% i% $* (!e( (!e( *ari)s ! i%(i% t$ t-e -ar"*'& *ree "eta "eta&& i$%s i$%s a%( a%( re"$ e"$i% i% t-e" t-e"// It a&s$ ets ri( $* resi(' i('e &e* &e*t $% r$i&ers r$i&ers i%('stria i%('stria&& e'i#"e%t e'i#"e%t;/ ;/ T-e )-e&at )-e&ati% i% #r$#e #r$#ert! rt! $* EDT EDTA, i% t-e 9e&( 9e&( $* "e(i "e(i)i )i%e %e,, )a% )a% e 'se( 'se( t$ #ree #ree%t %t #re)i #re)i#it #itati ati$% $% i% e!e (r$# (r$#s s a%( a&s$ t$ #ree%t i%*e)ti$%s )a'se( ! ra"?%eatie a)teria t-at -ae )a&) )a&)i' i'" " a%( "a% "a%es esi' i'" " i% t-ei t-eirr $'ter $'ter )e&& )e&& a&&s a&&s// EDTA EDTA )a% )a% a&s$ a&s$ e 'se( t$ treat #atie%ts s'@eri% &ea(
T-e EDTA EDTA a%( Ca2= st$). st$). s$&'ti$%s s$&'ti$%s ere #re#are( as e&& as a% H + H>= '@er s$&'ti$%/ T-e 500 "L 0/1 M st$). EDTA EDTA s$&'t &'ti$% i$% as "a(e ! eiei-i% i% 1/6120 $* a 2H2EDTA?2H2O )r!sta&s a%( tra%s*erri% it t$ a >00? "L ea. ea.er er// A $&'" $&'"e e $* 200 200 "L (isti&&e( ater as a((e( t$ (iss$&e it a%( t-e% 1/0 $* MC& 2?6H2O )r!sta&s as a((e(/ T-e s$&'ti$% as tra%s*er tra%s*erre re( ( t$ a 500?"L 500?"L $&'"etr $&'"etri) i) Jas. a%( (i&'te( t$ "ar./ T-e 100 "L 0/05 st$). Ca 2= s$&'ti$% as set ! ei-i% 0/>17 $* / /K K #'re #'re Ca CaCO CO i%t$ i%t$ a 250? 250?"L "L ea. ea.er er// A% a"$' a"$'%t %t $* >0? >0?"L "L $* (isti&&e( ater as a((e(/ A -!(r$)-&$ri) a)i( HC&; s$&'ti$% as a&s$ a&s$ a((e a((e( ( t$ (iss (iss$ $&e &e t-e t-e s$&i s$&i(s (s -i& -i&e e t-e t-e s$&'t s$&'ti$ i$% % is ei% ei% -eat -eate( e( a%( stirre(, a&t-$'- t-e #r$)ess $* a((iti$% "'st e s&$ t$ #ree%t t-e #r$(')ti$ #r$(')ti$% % $* )ar$% )ar$% (i$i(e (i$i(e -i)&ea(s t$ &$ss $* "ateria&/ T-e res'&ti% s$&'ti$% as tra%s*erre( t$ a 100?"L $&'" &'"etri) Jas. a%( (i&'te( t$ "ar., )$ere( a%( "ie(/ T-e H + H>= '@er s$&'ti$% it- a #H $* 10 as "a(e ! "ii ii% 1>/1 "L $* )$%)e%trate( 1>/ M H a%( 2/16 $* H >C& )r!sta&s/ T-e s$&'ti$% as tra%s*erre( tra%s*erre( t$ a 250?"L $&'"etri) Jas. a%( (i&'te( t$ "ar./ T-e #H as teste( it- t-e 'se $* a #H "eter/
T-e EDTA EDTA a%( Ca2= $r.i% s$&'ti$%s ere *r$" t-e st$). s$&'ti$%s/ A 250? "L 0/01 0/01 M $r. $r.i% i% EDT EDTA s$&'t s$&'ti$ i$% % as #re#are( ! "eas'ri% 25 "L $* t-e EDTA st$). s$&'ti$%, tra%s*erri% it t$ a 250?"L $&'"etri) Jas., a%( (i&' (i&'ti ti% % it t$ "ar. "ar.// F$r t-e t-e 50 "L 0/005 M $r.i% sta%(ar( Ca 2= s$&'ti &'ti$ $%, 5 "L $* t-e t-e st$). t$). Ca 2= s$&'ti$% as "eas're( $'t i% a 50 "L $&'" $&'"etr etri) i) Jas. Jas. a%( (i&'te (i&'te( ( t$ "ar./ T-e sta%(ar(i3ati$% sta%(ar(i3ati$% $* 0/01 M EDTA EDTA s$&'ti$% as ($%e ! #i#etti% 10 "L $* t-e $r.i% sta%(ar( Ca 2= s$&'ti$% i%t$ i%t$ ea ea))- $* t-e t-e t-r t-ree ; ; 250? 250?"L "L Er&e%"e!er Jas.s, it- t-e a((iti$% $* 75 "L (ist (isti& i&&e &e( ( ate aterr *$r *$r ea ea))-// A*ter ter t-e t-e a((i a((iti ti$% $% $* "L $* t-e t-e '@er s$&'ti$% a&$% it- (r$#s $* EBT EBT i%(i i%(i)a )at$ t$r, r, t-e t-e s$&'t s$&'ti$ i$% % as as titr titrat ate( e( itit- t-e t-e 0/01 0/01 M sta% sta%(a (ar( r( EDTA s$&'ti$% '%ti& a )$&$r tra%siti$% *r$ *r$" i%e i%e re( t$ )&ea )&earr &'e &'e as as $se $ser re( e(// T-e T-e sa"e sa"e as as ($%e ($%e *$r *$r t-e t-e 2 $t-e t-er s$&'t &'ti$%? i$%?)$ )$% %tai% tai%i% i% Jas.s/ F$r t-e a%a&!sis $* t-e (ri%.i% ater Hidde S5ri", 50 "L as "eas're( $'t *r$" t-e sa"#&e a%( as tra%s*erre( t$ a 250?"L Er&e%"e!er Jas./ Jas./ T-e T-e titrat titrati$% i$% #r$)e #r$)e('r ('re e as as sa"e it- t-at $* t-e sta%(ar(i3ati$% + a((i% "L $* t-e '@er s$&'ti$% a&$% it- (r$#s $* EBT i%(i)at$r t$ t-e s$&'ti$% a%( titrati% it it0/01 M sta%(ar( EDTA s$&'ti$% '%ti& t-e sa"e )&ear &'e )$"#&e a##e ##ears/ rs/ T-is as ($%e ($%e 2 "$re ti"es/
RESULTS AND DISCUSSION
U#$% t-e #re#arati$% $* st$). EDTA s$&'t s$&'ti$% i$% *$r *$r t-e sta%(a sta%(ar( r(i3a i3ati$ ti$% % $* t-e EDTA s$&'ti$%, MC&2?6H2O )r!sta&s ere a((e( t$ (iss$&e t-e EDTA sa&t ('e t$ (ierse i$% e@e)t a%( a&s$ t$ e%s're a s-ar# e%(#$i%t ('ri% titrati$% Ca?EBT is %$t er!
sta&e;/ As a res'&t, t-e )$"#&e M? EDTA *$r"s/ Be)a'se EDTA is i%s$&'&e i% ater a%( i&& (iss$&e -e% -e% t-e t-e #H is %e't %e'tra ra&i &i3e 3e( ( t$ , aOH #e&&ets ere a&s$ a((e( *$r t-e *a)i&itate( (iss$&'ti$% $* EDTA i% a)i( *$r", *$r", a&$% a&$% itit- t-e a##&i) a##&i)ati ati$% $% $* -eat i% t-e s!ste" -i&e stirri% it/ A&s$ &s$, t-e! are a((e( t$ (is#e& t'ri( t'ri(it! it! i% t-e s$&'t s$&'ti$% i$%// H$e H$eer er,, a((iti$% $* e)ess aOH #e&&ets "a! res'&t i% t-e *$r"ati$% $* t-e #re)i #re)i#it #itate ate Ma Ma%e %esi' si'" " H!(r$ H!(r$i( i(e e MOH;2; -i)-i)- i&& i&& '#se '#sett t-e t-e #H a&a%)e/ EDTA as sta%(ar(i3e( t-r$'- t-e titrati$% $* t-e CaCO $r.i% sta%(a sta%(ar( r( s$&'t s$&'ti$% i$%,, itit- EBT EBT as t-e = i%(i)a i%(i)at$r t$r a%( H?H> s$&'ti$% s$&'ti$% as t-e '@er/ T-e "$&e sta%(ar(i3ati$% rati$ rati$ $* EDTA:C EDTA:Ca a 2= *r$" *r$" t-e Ca CaCO CO sta%(ar sta%(ar( ( is 1:1/ T-e )$%)e%tra )$%)e%trati$% ti$%s s i% "$&arit! $* EDTA *$r t-e t-ree ; tria&s ere $tai%e( 'si%, asi)a&&!, t-e t-e "$&ar &ar )$%) )$%)e e%tr %trati$ ti$% $* t-e t-e #ri"ar! sta%(ar( CaCO , its $&'"e, a%( t-e $&'"e $* t-e EDTA s$&'ti$% %ee(e( %ee(e( *$r *$r t-e titra titrati$ ti$%/ %/ Ta+,% ';/ T-e aerae "$&arit! $* EDTA EDTA as )$"# )$"#'t 'te( e( as as 0/00 0/005 5 M re* re*er er t$ a##e%(i B *$r )a&)'&ati$%s;/
Ta+,% '/ T-e res'&ti% "$&ar )$%)e%trati$%s $* sta%(ar(i3e( EDTA
T$!a ,
VCa/II& 0d.
N% VEDTA
1
10 "L
7/ "L
'
10 "L
/ "L
(
10 "L
/2 "L
2EDTA3 0/0062 M 0/0056 M 0/0060 M
O%&! a s"a&& a"$'%t $* i%(i)at$r as a((e( a((e( e)a's e)a'se e t-e a((it a((iti$% i$% $* t$$ "')- i%(i)at$r $'&( )a'se a i(e ra%e ra%e $* resista esista%)e %)e i% #H )-a%e )-a%e,, "a.i% t-e e%(#$i%t %$t er! s-ar#/ As t-e EBT i%(i)at$r as a((e(, t-e res'&ti% )$&$r $* t-e s$&'ti
%$ a##ea a##ears rs t$ e )&$se )&$serr t$ #i%. #i%.i$& i$&et et t-a% t-a% i%e i%e re( as as e#e e#e)t )te( e( i% t-e t-e ater ter sa" sa"#&e #&e a%a&! %a&!s sis;/ is;/ T-is is e)a'se t-e M?EBT )$"#&ees are t-e t-e "ai% "ai% rea eas$ s$% % *$r *$r t-e t-e i%e i%e?r ?re( e( 2= )$&$ )$&$rr a%( a%( t-er t-ere e are are %$ M i$%s #res #rese% e%tt i% t-e t-e Ca CaCO CO s$&'t s$&'ti$% i$% t$ )$"#&eate it- EBT a%( *$r" t-e )$&$r )$&$r/ T-e Ca2= i$%s i$%s #res #rese%t e%t i% t-e CaCO s$&'ti$% are t-e $%es $'%( t$ EBT/ 2=
Ca
2−
=H =HI%
→
CaHI% /1&
At t-e e%(#$i%t, t-e Ca2= i$%s i% t-e s$&'ti$% are (is#&a)e( *r$" t-e Ca? EBT )$"#&e ! EDTA + '%i%(i% t$ t-e M2= i$%s + e)a'se t-e Ca?EDTA Ca?EDTA )$"# )$"#&e &e -as -as a -i-i-er er *$r *$r"ati "ati$% $% )$%s )$%sta ta%t %t,, * * , t-a% t-e M?EDTA )$"#&e/ Ca2= =MH2<
→ CaH2< =M2 + /'&
M2= =CaHI%
→
MHI% M HI% =Ca2 + /(&
T-is "ea%s t-at t-e EDTA EDTA -as a reater te%(e%)! t$ )$"#&eate itCa2= i$%s t-a% M 2= i$%s/ H$eer, t-e t-e Ca Ca?E ?EDT DTA A )$"# )$"#&e &e is '%st '%sta a&e &e e)a'se it re'ires a -i-er e%er! i% $r(er t$ *$r" Ta+,% (;/ T-is is -!, -!, i% #re# #re#ar ari% i% t-e t-e st$) st$). . EDT EDTA s$&'ti$% s$&'ti$% *r$" *r$" t-e ei%%i%, ei%%i%, MC&2? 6H2O )r!sta&s ere a((e( t$ e%-a%)e t-e e%(#$i%t $* t-e titrati$%/
Ta+,% (/ T-e )$"#&e *$r"ati$% )$%sta%t * *; a&'es a%( -ierar)-!
456-,%7
K8
Ca?EDTA 5/0 1010 M?EDTA >/ 10 M?EBT 1/0 107 Ca?EBT 2/5 105 Ca?EDTA M?EDTA M?EBT Ca? EBT Li.eise, t-e M?EDTA )$"#&e -as a reater * * t-a% t-a% t-e M?EBT )$"#&e
a+,% (;/ T-is Ta+,% T-is "ea% "ea%s s t-a t-at a*te a*terr 2= ass ass'" '"i% i%; ; a&& a&& t-e t-e Ca i$%s i$%s are are )$%s'"e( ! EDTA, it i&& 2= )$"#&eate it- t-e M i$%s %et a*te a*terr it (is# (is#&a &a)e )es s t-e t-e i$% i$% *r$" *r$" t-e t-e M?EBT M?EBT )$"#&e )$"#&e// T-is i&& res'&t res'&t t$ t-e &$%e EBT i$%s i% t-e s$&'ti$%/ T-e a##eari% )$&$r, -e%)e, is )&ear &'e/ MHI% =H2<2−
→
MH2< =HI%2− /)&
T-e titer "a%a&!te #er "Ltitra%t; $ta tai%e i%e( as as 0/5 0/5 re re*er *er t$ a##e%(i B *$r )a&)'&ati$%s;/ F$r t-e ater F$r ater sa"#& sa"#&e e a%a&! a%a&!sis sis,, t-e ater sa"#&e as titrate( it- t-e sta%(ar(i3e( EDTA *$r t-e (eter"i%ati$% (eter"i%ati$% $* its t$ta& -ar(%ess $r t$ta& i$% )$%te%t/ It is e#resse( i% ##" N#arts N#arts #er "i&&i$ "i&&i$% % e)a' e)a'se se it "eas'res t-e ei-t $* t-e "i%era& )a&)i'" a%( "a%esi'"; #er 1 &iter $* t-e s$&'ti s$&'ti$% $% i% t-is t-is e#er e#eri"e i"e%t, %t, (ri%.i% ater;/ U#$% U#$% #re#a #re#ara rati$ ti$% % $* ater ater sa"#& sa"#&e e s$&'ti$%, t-e i%e?re( )$&$r a##ears as t-e EBT i%(i)at$r as a((e( t$ t-e s$&'ti$%/ T-is is e)a'se $* t-e M?EBT )$"#&e *$r"e(/ M2= =HI%2−
→ MHI% /9&
T-e EBT i%(s it- t-e M2= i$%s #rese #rese%t %t i% t-e ater ater sa"#& sa"#&e e "$re "$re 2= t-a% it ($es it- t-e Ca i$%s e)a e)a'se 'se M?EB ?EBT )$"#&e #&e -as -as a -i-er * * t-a% t-e Ca?EBT )$"#&e )$"#&e a+,% (;/ T-is "ea%s t-at t-e Ta+,% *$r"ati$% $* M?EBT is "$re *a$re(/ Be*$re t-e e'ia&e%)e #$i%t ('ri% titrati$%;, t-e titra%t, -i)- )$%sists $* M?EDTA )$"#&ees, as a((e( t$ t-e s$&'ti$%/ T-e M2= i$%s *r$" t-e M?EDT M?EDTA )$"#&e )$"#&e are (is#&a)e( (is#&a)e( ! 2= t-e Ca i$%s i% t-e ater sa"#&e t$ *$r" t-e )$"#&e Ca?EDTA, as -at a&s$ -a##e%e( i% t-e sta%(ar(i3ati$% $* t-e EDTA s$&'ti$%/ At e%(#$i%t, t-e M 2= i$%s *r$" t-e M?EBT )$"#&e 9; rea)t it- EDTA,
*$r"i% *$r"i% t-e M?EDT M?EDTA A )$"#&e/ )$"#&e/ T-e *ree EBT i$%s &e*t ('e t$ t-e (is#&a)e" (is#&a)e"e%t e%t ); )a's )a'se e t-e t-e )&ea )&earr? &'e )$&$r $* t-e s$&'ti$%/ T-e (ri%.i% ater 'se(, Hidde S5ri", -as a "i%era& )$%te%t $* 25 ##" )a&)i'" a%( 5 ##" "a%e "a%esi' si'"/ "/ T-e$r T-e$reti eti)a& )a&&!, &!, it -as a t$ta& -ar(%ess $* 206/55 ##"/ T-e atat-er ere( e( (ata (ata i% t-e t-e e#e e#eri ri"e "e%t %t s-$ t-at t-e e#eri"e%ta& aerae t$ta& -ar(%ess $* t-e ater sa"#&e is a+,% );/ T-e 11/ 11/7> 7> ##" ##" Ta+,% T-e t$ta t$ta&& -ar(%ess -ar(%ess as (eter"i%e( (eter"i%e( t-ree t-ree ; ti"es *$r )$"#aris$% a%( #re)isi$%/ A ?test at 5K )$%9(e%)e &ee& as #er*$r"e( t$ $"it a #$ssi&e $'t&ier/ A&& (ata are a))e#te(/ T-e )a&)'&ate( t$ta& -ar(%ess *$r ea)- tria& i%$&e( t-e t-e tite titerr a&' a&'e, e, t-e t-e %et %et $&' $&'"e "e $* EDTA, a%( t-e $&'"e $* t-e ater sa" sa"#&e #&e re re*er *er t$ a##e% ##e%( (i B *$r *$r )a&)'&ati$%s;/
Ta+,% ). Data *$r t-e ater sa"#&e a%a&!sis
T$!a, V0a6-,% N% VEDTA T5a, Ha$dn%00: --6
A;%$a"%
1
'
(
50 "L 50 "L 50 "L 1>/0 21/1 1/> "L "L "L 166/0 250/2 15/ > 5 2 11/7> ##"
T-e$reti)a&&! T-e$reti)a&&! a%( e#eri"e%ta&&!, e#eri"e%ta&&!, t-e Hidde S5ri" S5ri" ater ter sa" sa"#&e #&e *r$" Hidde )a% e )&assi9e( as er! -ar( e)a'se t-e! are $t- reater t-a% 9;/ 10 ##" Ta+,% T-e e#e e#eri ri"e "e%t %ta& a& a&' a&'e e (i@e (i@ers rs i% t-e t-e t-e$r t-e$reti eti)a& )a& a&'e a&'e ! 7/1 7/1K, K, -i)-i)"ea%s "ea%s t-e e#e e#eri" ri"e%t e%t as as a&"$s a&"$stt a))'rate/
Ta+,% 9. T-e ater -ar(%ess s)a&e
Wa%$ Ha$dn%00
--6 CaCO(
S$*t M$(erate&! s$*t M$(erate&! -ar( Har( Ger! -ar(
0 + 20 20 + 60 61 + 120 121 + 10 reater t-a% 10
Stat Statis isti ti)a )a&& #ara #ara"e "ete ters rs e erre a&s$ a&s$ ea& ea&'a 'ate te(/ (/ T-e T-e re&at e&ati ie e sta% sta%(a (ar( r( (eiat (eiati$% i$% as as 26>/ 26>/2 2 ##t, ##t, a%( t-e )$%9(e%)e &i"its $tai%e( ie% ! t-e )$%9(e%)e )$%9(e%)e i%tera& i%tera& ere ere 65/6 65/6 ##" a%( 17/5 ##"/ Err$rs i% t-e e#eri"e%t "a! e a res'& res'&tt $* $erti $ertitra trati$ ti$% % e)a' e)a'se se t-e )&ear?&'e )$&$r $* t-e e%(#$i%t is %$t eas! t$ (isti%'is- *r$" t-e #'r#&e )$&$r a*ter t-e i%e?re( )$&$r;/ T-e )$&$r s-i*t "a! a&s$ e s&$ a%( s$ i&& e t-e (ete)ti$% $* its )-a%e/ T-e ei-t $* t-e CaCO a%( EDTA )r!sta&s i% t-e ei%%i% )a% a&s$ e a s$'r)e $* err$r si%)e t-e! "i-t e a@e) @e)te( te( ! t-e a))' a))'rra)! $* t-e a%a& a%a&!t !ti) i)a& a& a&a a&a%) %)e/ e/ T-e T-e #H "ete "eterr 'se( i% (eter"i%i% t-e ea)t #H $* t-e a""$ a""$%ia %ia '@er '@er s$&'t s$&'ti$% i$% "i-t "i-t a&s$ ear i%a))'ra)!/ A&s$, t$$ "')$r i%a(e'ate a"$'%t $* t-e i%(i)at$r )a% )a'se a% ear&! $r &ate e%(#$i%t/ H'"a% a%( #ara&&a err$rs a&s$ )$%tri' i'te si%) i%)e $%e "a! "ist "ista a.e &i%e &i%es s i% t-e t-e 'r 'rette ette,, *$r *$r ea"#&e, as a (i@ere%t a&'e/
SUMMARY AND CONCLUSIONS
EDTA as 'se( as t-e titra%t e)a'se it is a )-e&ati% ae%t a&e t$ rea)t it- a "eta& i$% at a 1:1 st$i)-i$"etri) rati$/ I% sta%(ar(i3ati$% $* t-e EDTA s$&'ti$% t$ (eter"i%e its ea)t "$&ar )$%) )$%)e% e%tr tra ati$% ti$%,, / /K K Ca CaCO CO as 'se( as t-e #ri"ar! sta%(ar(/ Ma%e Ma %esi' si'" " )r!st )r!sta&s a&s e ere re a((e( a((e( i% t-e EDTA *$r e%-a%)e( s$&'i&it!/ T-e i%(i)at$r 'se(, EBT, is a "eta&& "eta&&$)$)-r$ r$"i) "i) i%(i)a i%(i)at$ t$rr t-at t-at -as )$"#&ees $* (i@ere%t )$&$rs
)$"#are( t$ t-e reae%ts/ T-e H ? H>= '@er s$&'ti$% it- a #H $* 10 as 'se( e)a'se t-e )a&)i'" a%( "a%esi'" "a%esi'" )$"#&ee )$"#&ees s *$r" *$r" i% t-is .i%( $* e%ir$%"e%t/ T-e e%(#$i%t i% t-is #H is a&s$ eas! t$ (ete)t e)a'se t-e s-i*t $* t-e )$&$r $* EBT is *r$" i%e?re( t$ )&ear?&'e/ A*ter sta%(ar(i3a i3ati$% i$%, t-e $tai% tai%e e( aerae "$&ar )$%)e%trati$% $* EDTA it- %$ $'t&ier i% t-e (ata; is 0/005 M/ T-e )$"#'te( titer as 0/5 / T-is as 'se( t$ )$"#'te t-e a"$'%t $* CaCO i% ##" #rese%t i% t-e ater sa"#&e/ I% t-e t-e ate aterr sa"# sa"#&e &e a%a& a%a&!s !sis is,, t-e t-e Hidde S5ri" S5ri" as (ri% (ri%.i .i% % ate aterr Hidde titrate( it- t-e sta%(ar(i3e( EDTA s$&' s$&'ti ti$% $%// T-e T-e ate aterr sa"# sa"#&e &e -as -as a )a&) )a&)i' i'" " )$%t )$%te e%t $* 25 ##" ##" a%( "a%esi'" )$%te%t $* 5 ##"/ T-e sa"e #r$)e('re as i% t-e sta%(ar(i3ati$% as ($%e, a%( a*ter t-ree t-ree ; tria&s, tria&s, a&'e a&'es s $* t-e t$ta& t$ta& ##" )$%te%t ere $tai%e( + 166/0> ##", 250/25 ##", a%( 15/2 ##"/ T-e aerae ##" CaCO as 11/7> ##", ##", a )&$ )&$se a&' a&'e e t$ t-a t-at $* t-e t-e )&ai"e( )&ai"e( $r t-e$re t-e$reti)a& ti)a& ##" )$%te%t )$%te%t $* t-e t-e (ri% (ri%.i .i% % ate aterr -i)-i)- as as 206/ 206/55 55 ##"/ ##"/ T-e T-e t$ t$ 2; 2; a&'e a&'es s (i@er ! 7/1K/ Si%)e t-e t-e$reti)a& a%( e#eri" e#eri"e%ta e%ta&& t$ta& t$ta& -ar(%es -ar(%ess s $* t-e Hidde S5ri" S5ri" are (ri% (ri%. .i% i% ater Hidde $t- reater t-a% 10, t-e (ri%.i% ater )a% e )&assi9e( as er! -ar( ater a))$r(i% t$ t-e ater a+,% 9;/ T-is -ar -ar(%es (%ess s s)a&e )a&e Ta+,% "ea%s t-at Hidde S5ri" is s'ita&e t$ e a (ri%.i% ater si%)e it )$%tai%s e%$'- a"$'%t $* "i%era&s #arti)'&ar&! Ca2= a%( M2= i$%s;/ S$"e S$"e err err$rs $rs "a! "a! e )$"i )$"i% % *r$" *r$" $ert $ertitr itrat ati$% i$% $* t-e s$&'t s$&'ti$% i$%,, a &ate &ate (ete)ti$% $* t-e )$&$r )-a%e e)a'se $* its &ate tra%siti iti$%,
i%a))'ra)! $* e'i#"e%t, t$$ &ess $r t$$ t$$ "')"')- a((i a((iti ti$% $% $* i%(i i%(i)a )at$ t$rr $r '@er, '@er, a%( s$"eti"e s$"eti"es s a( rea(i% rea(i% $* t-e (ata/
REFERENCES
N1 N1 Qe%, e%, A&&e &&e%/ EDT EDTA/ UCD$;i* Che2i!i/ We/ 6 A#r/ 2015/ -tt#:)-e"i.i/')(ais/e('I%$ra %i)C-e"istr!C$$r(i%at %i)C-e"istr!C$$r(i%ati$%C-e"istr i$%C-e"istr !Lia%(sEDTA/ N2 E#eri"e%t/ Che2i*%r4 ?@71 ?d ri%%e L$.+r$%+r4 E6$2i$%i+ Re;ie#er A7Y7 ?010 ' ?011 / We/ 6 A#r/ 2015/ -tt#s:rea.t-e&i-t/9&es/$r(#res s/)$"20101)-e"istr!?26?1?2%(? &a$rat$r!?ea"i%ati$%? reieer/#(*/ Geer$ N Petr'))i, Ra-/ Che2 Che2i* i*%r %r4 4 Pri Prii5 i5e* e* $d $d M+de M+der r A55i$%i+*/ 10t10t- e(/ O%tar O%tari$ i$ Cit! Cit!: Pears$% Ca%a(a, 2011/ 1>26/ Pri%t/
N> S$'t-a!, Dr/ C/ C$"#&e C$"#&e$ $"etr "etri) i) Titrat Titrati$%s i$%s EDTA/ EDTA/ APCH?&1 Che2i$ A$4*i*/ Dr/ C/ S$'t-a!/ We/ 6 A#r/ 2015/ -tt#:)-e"i%%ere/'.3%/a)/3a&i rariesa#)-21-$e%(ers%$tes a#)-21e(ta/sJ/as-/ N5 De La Ca"#, U&ri)-, a%( O&ier See&!/ C$"#&e$"etri) Ca C+25e6+2e%ri i C$ Deter"i% Deter"i%ati$ ati$%/ %/ C+25e6+2e%r De%er2i$%i+/ We/ -tt#:/)s'(-/e('$&ier)-e2 0&a"a%'a&)a&)i'"/-t"/ N6 Hare!, Dai(/ Titri"etri) M+der Met-$(s $* A%a&!sis/V A$4%i$ Che2i*%r4 / 1st e(/ M)ra?H M)ra?Hi&& i&& C$"#a%ie C$"#a%ies, s, 2000/ 2000/ 16/ 16/ Pri%t/
APPENDIX A DATA SHEET EPERIMENT
QUANTITATIVE DETERMINATION OF TOTAL HARDNESS IN DRINKING WATER BY COMPLEXOMETRIC EDT E DTA A TITRA TITR ATION Sanda$d!
Sta%(ar( CaCO s$&'ti$% Wei-t $* #'re CaCO: 0/>17 F$r"'&a "ass $* 1 sta%(ar(: 100/06 K P'rit! $* #'re CaCO : /K G$&'"e $* 9%a& s$&'ti$%: 100 "L ◦
W$r.i% sta%(ar( CaCO s$&'ti$% G$&'"e $* sta%(ar( CaCO s$&'ti$%: 50 "L G$&'"e $* 9%a& s$&'ti$%: /15 "L
T$!a,
1
'
(
G$&'"e $* $r.i% CaII; sta%(ar(, "L
10
10
10
Fi%a& $&'"e $* EDTA, "L
10/6
11/5
1/7
I%itia& $&'"e $* EDTA, "L
2/7
2/7
11/5
et $&'"e $* EDTA, "L
7/
/
/2
M EDTA
0/0062
0/0056
0/0060
Aerae M EDTA
0/005
Titer
0/5
Sa6-,% Ana,=0!0
Bra%( $* "i%era& ater 'se(: Hi((e% S#ri% Mi%era& Water )$%te%t ##" Ca: 25 ##" M: 5
##" CaCO *r$" ##" Ca: 62/>2 ##" ##" CaCO *r$" ##" M: 1>>/127 ##"
T$ta& T$ta& Water Water Har(%ess: Har(%ess: 206/55 206/55 ##"
T$!a, G$&'"e $* ater sa"#&e, "L Fi%a& $&'"e $* EDTA, "L I%itia& $&'"e $* EDTA, "L et $&'"e $* EDTA, "L
T$ta& T$ta& Har(%ess Har(%ess Aerae RSD C$%9(e%)e I%tera&
1 50 15/5 1/5 1>/0 166/0> ##"
' ( 50 50 26/7 2/ 5/6 15/5 21/1 1/> 250/25 15/2 ##" ##" 11/7> ##" CaCO 26>/2 ##t 11/7> 126/11; ##" CaCO
APPENDIX B SAMPLE CALCULATIONS AND WORKING EQUATIONS
Sanda$d!
1 "$& 1 "$& Ca2= ÷ ( /K) ÷ "$& Ca 100/06 06 1 "$& CaCO ÷ 100
"$& Ca2=X ( 0/>17 CaCO )
≈
1/
0/00>1 "$& Ca2=
>/E07622A 10?A "$& Ca2= 1000 "L 1 X ÷ ÷ ÷ 100 "L st$). Ca2= 1 L 1 0 ≈ 0/00>E1 M Ca2=
2=
M Ca
X>/07622 10? "$& Ca2=
X>/E07622A 10?A M Ca2=
2/
( >/07622 10? M Ca2=) ( 10 "L Ca Ca2=) ÷ M1 EDTA X ÷ 7/ "L "L EDTA EDTA 0/006 62 M1 EDTA EDTA ≈ 0/00
X6/212>>6 10? M1 EDTA
/
( >/07622 10? M Ca2=) ( 10 "L Ca Ca2=) ÷ M2 EDTA X / "L EDTA EDTA ÷ 0/0056 56 M2 EDTA EDTA ≈ 0/00
X5/5771161 10? M2 EDTA
>/
( >/07622 10? M Ca2=) ( 10 "L Ca Ca2=) ÷ M EDTA X ÷ /2 "L "L EDTA EDTA 0/006 60 M EDTA EDTA ≈ 0/00
5/
M1 =M2 =M ÷
M EDTA X
X5/2>2626 10?
X5/51751 10? M EDTA
≈ 0/005 M EDTA
6/
100/06 CaCO X0/ Titer Titer CaCO X 5/2>2626 10? M EDTA EDTA ÷ X0/500206 L "$&
(
≈
)
0/5
L
≈
0/5
" CaCO "L EDTA
Sa6-,% Ana,=0!0 1. ##" CaCO *r$" ##" Ca a%( ##" M *r$" ##" Ca
CaCO O 100/06 1 "$& CaC = ( 25 ##" Ca) 1 "$& Ca÷ CaCO÷ = ÷ >0/07 1 "$& Ca 1 "$& ≈ 62/>2 ##" CaC CaCO O
1 "$& M÷ 2>/A05
*r$" ##" M X( A5 ##" M)
≈
A 1 "$& MCO ÷ 1 "$& M
62/>20075 ##" CaCO
1 "$& CaCOA 100/06 1 "$& CO ÷ 1 "$& CaCOA÷ A
X1>>/1271A>A ##" CaCOA
1>>/127 1>>/127 ##" CaCOA
2/ T$ta T$ta&& -ar(%e r(%ess X( ##"CaCO *r$" *r$" ##"Ca) = ( ##" ##" CaCO *r$" *r$" ##"M) X206/551>1 ≈ 206/55 55 ##" ##"
(. ##"1 CaCO
0/500206 ÷ ( 1> "L EDTA EDTA )÷ 0/500206 L ÷ 1000 " = ÷ = 50 "L sa"#&e ÷ 1 ÷ ≈ 166/ 166/0> 0> ##"1 CaCO
166/ 166/0> 0>07 075 57 7 ##"1 CaCO
). ##"2 CaCO
0/500206 ÷ ( 21/1 "L EDTA EDTA )÷ 0/500206 L ÷ 1000 " = ÷ = 50 "L sa"#&e ÷ 1 ÷ ≈ 250/2 250/25 5 ##"2 CaC aCO O
250/ 250/2> 2>71 71> >1 1 ##"2 CaCO
5/ ##" CaCO
0/500206 ÷ ( 1/> "L EDTA EDTA )÷ 0/500206 L ÷ 1000 " = ÷ = 50 "L sa"#&e ÷ 1 ÷ ≈ 15/ 15/2 2 ##" CaC aCO O
15/ 15/2 2>7 >752 52 ##" CaCO
6/ ##" CaC CaCO
( 166/0>0757 166/0>0757 + 250/2>71>1 250/2>71>1 + 15/2>752 15/2>752) ##" CaCO CaCO = 11/7757 ≈ 11/7> 11/7> ##" CaCO CaCO ÷ = 11/7757
7/ S
=
##") ( 166/0>0757 ? ##
2
+ ( 250/2>71>1 ? ## ##") + ( 15/E2>752 ? ## ##")
2
( A ? 1)
RSD RSD /
2
50/7557>07 ##" ##" CaCO CaCO 1000 ##t ) = = ÷ ( 1000 11/7757 ##" CaCO
=
50/7E557>07
26>/ 26>/22 2272 72
≈
≈
50/0 ##" CaCO CaCOA
26>/ 26>/2 2 ##t
/ ( >/0 >/0) ( 50/75 50/7557> 57>07 07 ##" CaCO ) CI5K X11/7757 ##" CaCO W ÷ X11/7757 W126/105>05 ##" CaCO ≈ 11/7> W126/11 ##" CaC CaCO O
Add!!5na, -a$a6%%$0
1/
#er #er)e%t err$r err$r
( 206/55E1> 206/55E1>1E 1E ? 1E1/7A757 1E1/7A757AE AE) = 100K) = ÷ ( 100K 206/55E1>1E
7/175 7/175>5E >5E70 70K K
≈
7/1K 7/1K
APPENDIX C ATTACHED DATA SHEET